Each subscriber in conventional telephone systems is assigned a seven digit telephone number, and a three digit area code. On an international basis, each country is assigned a country code and often a city code.
In order to place a long distance telephone call one must dial at least ten separate digits. International calls often require a minimum of fifteen digits. In some situations additional digits are required to connect to a specific long distance telephone company or in order to get an outside line. In order to avoid the inconvenience of dialing a long sequence of numbers a technique called "speed dialing" has been developed. Speed dialing allows a subscriber to set up a database in which a one or two digit code is assigned to each telephone number. By dialing the one or two digit code, the subscriber can in effect cause the phone to dial a much longer number that is stored in a database.
Speed dialing is currently implemented using a number of different approaches. Some "intelligent" telephone units currently available include a speed dialing function which stores a database of telephone numbers in the telephone unit. The database is addressed from either a set of dedicated speed dialing keys which are identified with specific numbers, or using special keys each of which is associated with a particular telephone number stored in the unit. An enhancement to the speed dialing technique is provided in some intelligent units which is referred to as voice dialing. In this enhancement, a microphone provides an analogue signal in response to the user speaking a predetermined word or sound. Circuitry in the telephone converts the analogue signal to a digital signal which is related to the address of the memory location where the corresponding telephone number is stored. The address so generated is used to read the telephone number from memory. After the number is read from the memory each of the digits is converted to the corresponding dual tone multi frequency (DTMF) dial signal normally employed by the telephone system.
As an alternative to using an intelligent telephone to implement speed dialing, in some situations the facilities of the central telephone switch can be used to implement speed dialing. Some telephone companies permit a subscriber to establish a telephone number database that is maintained by the telephone company. The customer is permitted to use the database for speed dialing and to modify the database, following certain protocols established by the company. This implementation is attractive to subscribers who do not have telephones with sufficient "intelligence" to dial previously stored numbers.
While speed dialing does facilitate the use of a telephone, some users may be in the situation of employing one database at home and another database at work. The two databases usually have at least some common numbers, but these common numbers are often assigned to different codes in the two databases. Speed dialing errors can occur because a user experiences confusion between the contents of the two databases. With the introduction of cellular (portable) telephones users who have speed dialing on their cellular telephone can be faced with the task of coping with three different databases which have various speed dialing codes.
There are existing prior art devices which can eliminate the need for a user to have multiple speed dialing databases; however, primarily due to human factor considerations such devices have not gained wide acceptance. The existing devices include portable battery operated autodialing devices which can store a database of telephone numbers and when activated by the user provide audible dial tone or DTMF dial signals. By placing the device adjacent the microphone of a standard telephone, the tone signals are transmitted through air into the telephone system and are recognized as conventional DTMF dial signals by the telephone circuits. Such a device in theory avoids many of the problems encountered by the telephone user who must cope with multiple databases since with such devices a user always operates with the same database. However, the existing devices have limitations imposed by human factor considerations and by the differences that exist among the various technologies used by different telephone installations and networks thus they have not achieved widespread acceptance and use.
Each telephone handset in a conventional hard wired telephone system is connected to the local switching exchange by telephone wires. Thus, each phone has a fixed location In order to accommodate people during periods when they are moving between fixed locations, two technologies have been developed, namely, radio paging and mobile or cellular telephones. The current state of the art in radio paging technology involves broadcasting a radio frequency signal to a number of subscribers who are in the range of the transmitter. Each subscriber has a battery operated device that includes a receiver and control circuitry which can identify when the transmitted signal is addressed to the particular subscriber. Some paging devices called "tone" pagers only provide the subscriber with an indication that he is being paged. The user then can respond by going to a telephone and calling a specified telephone number to receive the message, which is to call another number.
In more advanced pagers a small display is provided which can display a telephone number. In still more complex pagers actual messages are displayed, either in the form of icons which represent predetermined responses that the subscriber is requested to take, in actual text that is often abbreviated or cryptic, or in a voice message.
While paging devices do improve the capability of an individual to respond to telephone callers wanting telephone access to an individual who is not at a designated location, the individual who is paged is required to manually enter (i.e. dial) a telephone number in order to call back the person who placed the page. The present invention is directed to a system and method for enhancing the capability of the user of a radio pager to respond to a received message requesting the user to call a designated telephone number. Furthermore, the present invention provides for a personal speed dialing database in the form factor of an electronic wristwatch.